Hydrocarbon refining apparatus



H. C. REED ET AL HYDROCARBON REFINING APPARATUS Original Filed July 2,1948 Nov. 16, 1954 United States Patent O HYDROCARBGN REI-TIN INGAPPARATUS Homer C. Reed, Glendale, and Clyde H. 0. Berg, .Long

Beach, Calif., and Charles B. Lefert,'Library, Pa., assignors to UnionOil Company of California, Los Angeles, Calif., a corporationofCalifornia Original application July 2, 1948, Serial No. 36,724. Di-

vided and this application September 3, 1949, Serial No. 114,044

9 Claims. (Cl. 23-260) This invention relates to a process and apparatusfor the rening of heavy oils such as crude petroleum, straight run andcracked residuums, .coker distillates, mineral oils such as thoserecovered from shale, tar sand, diatomite, and miscellaneous .bituminoussands which may or may not be contaminated with undesirable elernentssuch as nitrogen, oxygen and sulfurcontaining hydrocarboncompounds,.coal oil fractions, particularly those of high densityrecovered from the distillate produced during coal coking which may becontaminated with acid or basically reacting constituents. for theproduction of lighter products such as liquids boiling below about 800F., fractions of which are suitable for fuels in internal combustion`engines and diesel engines, lubricating oils,. solvents, miscellaneousnaphthas, and the like. This is a division` of our copending applicationSerial No. 36,724, led July 2, 1948 now Patent No. 2,614,067.

More particularly this invention relates to refining processes for theconversion of .high density or low A. P. I. gravity oils lto products oflower boiling range and lov/er density which involve coking these oilsto form coke and avcoker distillateandhydrogenating the distillate inthe presence of water, `and a metal capable of reacting with water toform hydrogen.

The hydrogenation of mineral oils7 and the like, is well known `in theart. Generally this has been accomplished by subjecting the oil to behydrogenated to temperatures of from 200 F. to about 680 F. and fromabout l atmosphere to ashigh as about` l0() atmospheres of hydrogen inthe presence of ia hydrogenation catalyst usually comprising one. ofthe. noble'metals such as platinum or palladium, or oxides thereof. Theprincipal dis advantages of such processes include expensive andcornplex hydrogenation equipment, fextensive compression t.

facilities forraising the hydrogen pressure to the level required by theprocess, expensive, sensitive and easily poisoned catalysts which mustbeemployed, and the problem of catalyst recovery.

lt is an object of this invention to provide an easily controlled andetcient process fort-he hydrogenation of heavy oils for-'the productionof lower boiling fractions.

Another object of this invention is to provide ya process for convertinghigh density oilsfwhich may be contaminated with undesirableconstituents to desirablefproducts of lower boiling range and densityincluding the steps of coking the high density oil in the presence ofspent solids from the hydrogenation operation, simultaneouslyregenerating the spent solids and converting the coke to producer gasand employing the regenerated solids in the production of .hydrogen andthe simultaneous hydrogenaticn ofthe heavy oil.

Another object of this invention is to provide an improved process forthe recovery of elemental sulfur from sulfur contaminated crudepetroleum.

A further object of this invention is to provide an improved processpfor the reduction of oxides of metals such as iron to lower oxidationstates or to their elemental form whichinvolves steps of laying down alayer of eolie on the oxide particles and'reacting the coke-laden oxideat elevated temperatures in a lluidized vessel to produce producer gasand the metal in a nely divided ate.

Another object of this invention'is to provide an improved method forthe hydrogenation of heavy oils which comprises reacting a finelydividedvmetal or oxide of a ice metal above hydrogen in theelectromotive series ofmetals with water in the presence of the oil tobe hydrogenated to form the metal oxide, recovering thef'metal`oxide'frorn the hydrogenated material, laying'down' a layer of'coke onthe oxide particles and converting the coke-bearing oxide to theelemental metal or tofa lower oxide for reuse as a hydrogenationcatalyst and asa source of hydrogen.

A further object of this invention-isto'provide an improved continuousprocess for the hydrogenation of oils with hydrogen' produced by thereaction of elemental iron with water or water vapor.

It is also an object of the present invention tot provide an apparatusby which the aforementioned processes may be effected.

Other objects and advantages of this invention will become apparent tothose skilled in the art as the description thereof proceeds.

Briefly, the preferred modification of this vinvention comprises thehigh temperature pyrolysis' of'hydrocarbon oils in the presence ofparticles of a spentvmetal oxide in a lluidized coking zone whereby alayer of coke is laid down on the particles and `lower boilinghydrocarbon pyrolysis products are formed, separating the coke-ladenoxide particles from the pyrolysisproducts, reacting the coke with thespent oxide particles in a fluidized reducing regenerating zone tofforrnregenerated particles, combining a portion of the regenerated particleswith at least` apart of the pyrolysis'product, subjecting the mixturethus formed to conditions of superatmospheric temperature andpressure inthepresence of water thereby hydrogenating the pyrolysis product andforming a spent metal-oxide, separatingdesirable fractions of thehydrogenating'product thus formed, recovering the spent oxideand-recycling it'withthe high density oil to be coked.

The process of the present invention eliminates'virtually all of theaforementioned'disadvantagesand employs an inexpensive ruggedcatalyst.The process further utilizes hydrogengenerated under superatmosphericpressure in the presence of the oil to be hydrogenated therebyeliminating the compression facilities usually required for highpressure hydrogenations. .The hydrogen is ygenerated from waterand ametal ora metal compound which also acts as a catalyst. The solidsemployed are readily recoverableif desired, and such small losses as dooccur are notimportant since the material is readily and inexpensivelyobtained.

In the process of this invention, the solids employed preferablycomprise a iinely` divided metal above hydrogen in the electromotive:series of'metals, which may or may not contain aminor quantity ofoxides or suldes ofthat metal, and which is also capable of reactingwith water for the liberation'of hydrogen. Such metals` as iron, zinc,cobalt, nickel, and the like,.may-be employed, those of atomic numberfrom 25 to 30 beingfsuitable with exception of copper as wellas thelower oxides of these metals. In the preferred modication of theprocess, finely divided iron of the type generally known as sponge iron,is preferred. Thesematerials are rugged, easily recovered, highlyreactive under the conditions of the process, and relativelyinexpensive. :The iron particles may be prepared in `a variety ofmanners, although the preferred method involves the reductionof finelydivided iron oxides known as mill scale obtainable from such sources asrolling mills and the like. The solid particles may also bepreparedbythe reduction of finely ground and naturally-o`ccurring iron oxides orfrom other sources.

In the coker, reducing regenerator, and the oxidizing regenerator,uidized suspensions of solids are established in gaseous mixtures in acondition of `hindered settling. The gases move upwardly while thesolids slowly settle and a thorough countercurrent contact is effectedas well as precise temperature control. The iron serves to decomposewater to produce the required hydrogen and also perform as a mildhydrogenation catalyst.

During the hydrogenation step of the .combination process of thisinvention, the sponge iron catalyst is commingled with the oil to behydrogenated and a predetermined quantity of water to form a slurry.This slurry is introduced at high pressures through a heater into anagitated hydrogenation vessel. A completely liquid phase reaction occursat temperatures sufficiently high to effect the reaction of water andelemental iron and which may be as high as to cause furtherdecomposition of the hydrocarbon to be hydrogenated. By carefullycontrolling the temperature of the hydrogenation, a variable degree ofdestructive hydrogenation or combined hydrogenation and cracking may beeffected in the presence of iron which may also act as a hydrogenationcatalyst as well as the source of hydrogen. During this hydrogenationreaction, the iron is converted to iron oxide. Hydrogenated oil. ironoxide, and unreacted water, etc. are introduced into a suitableseparating device for recovery of the individual fractions of themixture. Such a separation may be effected in a conventionalfractionating column of the bubble tray type in which hydrocarbonfractions of any desired boiling range may be recovered along with theiron oxide and any residual oil. In such a system, the residual oilcontains iron oxide formed in the hydrogenation vessel and this residualfraction is preferably combined with the high density oil to be treatedand reprocessed.

Occurring simultaneously with the hydrocarbon h vdrogenation step is aneicient desulfurization by means of Which sulfur compounds aredecomposed with the ultimate formation of iron sulfides which areremoved with the iron oxides in the residual oil from the hydrogenationproduct fractionator. The process provides means for separation of ironsulfides from the iron oxides and the oxidation of such sulfides to formsulfur dioxide. The sulfur dioxide is subsequently converted toelemental sulfur by effecting a reaction of sulfur dioxide with carbonmonoxide contained in producer gas. The sulfur may be recovered eitheras a finely divided solid or as a liquid depending on the temperature.lf desirable, this sulfur dioxide may be further oxidized and convertedto sulfuric acid.

The nitrogen compounds which may be present in certain types of highdensity oils to be treated are decomposed under conditions ofhydrogenation with the formation of ammonia. Since the hydrogenation isaccomplished in the presence of water, the fractionator may be operatedunder such conditions so that the overhead temperature permits theremoval of an aqueous phase containing dissolved ammonia from the upperportion of the column.

The process and apparatus of the present invention may be more clearlyunderstood by reference to the drawing in which a schematic flow diagramof this invention is shown. To further facilitate the description and toalso provide a practical operating example of the process, the followingdescription of the drawing will be conducted in the form of an examplein which high density crude petroleum produced from the oil fields ofSanta Maria Valley (California) is the oil to be treated and in whichthe catalyst employed is sponge iron. Flow quantities are given andoperable ranges of pressure and temperature as well as preferredoperating pressures and temperatures are included.

Heavy oil cokz'ng Referring now more particularly to the drawing, 260barrels per day (42 U. S. gallons per barrel) of Santa Maria Valley(California) crude petroleum amounting to 43.9 tons per day is treatedaccording to the process of this invention. This heavy oil is preferablytopped for straight-nin gasoline recovery. The crude petroleum passesvia line 10 under pressure exerted by pump 11 through line 12 controlledby valve 13 and is combined with 49 barrels per day of coker residuumrecycled through line 14 controlled by valve 1S and with a streamcontaining 8 tous per day of hydrogenated residuum, 2.76 tons per day ofiron sulfide, and 20.9 tons per day of ferrie oxide flowing through line16 controlled by valve 17. The combined stream is introduced via line 18into heater 18a wherein it is heated to a temperature of from about 700F. to as high as about 1200 F. and preferably to about 900 F. The heatedstream then passes via line 19 into coker 20 wherein pyrolysis of thehydrocarbons is effected with the formation of hydrocarbon pyrolysisproducts of lower 4 boiling range and a mixture of iron oxide and ironsulfide particles laden with coke.

Coker 20 is a vessel in which the particles of iron compounds such ashigher oxides Fe304 and FezOz are maintained in a uidized state due tothe mixing action of hydrocarbon liquid and vapor being introduced fromheater 18a. The coke-laden iron compound particles are present in vessel20 in a state of hindered settling and act much as a high density fluidwhich accumulates in a lower portion of the vessel. Thus a level 21exists below which the coke-laden particles are in rapid motion,hindered from settling, and above which the particles tend to settleforming a solid-free gas space. Present within Coker 20 is separator 22by means of which particles of suspended iron compound are removed fromthe hydrocarbon pyrolysis product and returned to the lower portion ofthe vessel. Coker 20 preferably is operated at superatmospheric pressurefrom about zero to as high as 200 pounds per square inch gauge, andpreferably between about 30 and 100 pounds per square inch. Coke-ladenparticles of iron oxide and iron sulfide are removed from coker 20 bymeans of line 23 controlled by valve 24 and are sent thereby to reducer25.

The hydrocarbon pyrolysis products, as a vapor phase, pass fromseparator 22 by means of line 26 through cooler 27 and subsequently vialine 28 into coker bubble tower 29 wherein they are fractionated. Otherforms of distillation column such as a packed tower may be used as well.The overhead product passes by means of line 30 into cooler 31 wherein apartial condensation of the lower boiling hydrocarbons is effected. Thecombined liquid and gas pass via line 32 into separator 33 wherefrom theliquid products are withdrawn via line 34. A portion of this passes bymeans of line 3S controlled by valve 36 into the upper portion offractionator 29 as reflux while the remaining portion passes via line 37controlled by valve 38 to further processing facilities or storagefacilities not shown. This hydrocarbon stream comprises a coker gasolinewhich, depending upon the operation of coker bubble tower 29, may havean end point of from as low as about 150 F. to as high as 400 F. In thisoperation 23.6 barrels per day, or 2.65 tons per day of a 250 F. endpoint gasoline are produced.

The gas phase present in separator 33 is removed therefrom via line 39controlled by valve 40 and is introduced into absorber 41 in which theremoval of normally liquid hydrocarbon fractions from the gas iseffected. To effect this removal, a gas oil fraction is removed frombubble tower 29 by means of line 42, passed through cooler 43 andintroduced into absorber 41 by means of line 44 controlled by valve 45.This hydrocarbon fraction, a coker gas oil, passes downwardly throughabsorber 41 countercurrent to the upwardly rising gases and a dry gasconsisting substantially of hydrogen, methane, ethylene, ethane, and thelike, is removed by means of line 46 controlled by valve 47.

The rich absorption oil produced in absorber 41 is removed therefrom bymeans of line 48 a portion of which is returned via line 49 controlledby valve 50 to coker bubble tower 29 while the remaining portion passesby means of line 50a controlled by valve S1 to be hydrogenated ashereinafter described. The quantity of coker distillate thus producedfor hydrogenation amounts to 21.2 barrels per day, or 3.24 tous per day.

Metal oxide reduction Returning now to the treatment of the coke-ladeniron oxides and iron sulfides which are formed in coker 20, these solidparticles are collected in one portion of Coker 20 from which they areremoved by means of line 23 controlled by valve 24 at a rate of 31.4tons per day and introduced into reducer 25. This solid materialanalyzes, in per cent by weight, as follows:

Constituent: Weight per cent Iron Sulfide 8.8 Higher iron oxides 66.4Coke 22.0 Chloride 1.9 Sulfur e 0.9

Total 100.0

This material passes into the reducer at about 900 F.

The operation of the reducer is such that an effective carbon or cokeburn-ofi" from the solid particles upon .whichfthef coke was laid-downin, cokeraZt).` iseffected. The ,cokeis burned inthespresence of`an-.oxygen-con.- taining. gas such .as air. .to poduce .mainly carbon,m011- .oxide :This coke-.burnfofl isfcarried ,outat temperatures betweenabout 1400 F. and 1800 F. or higher. nA suitable; temperature forthis.reaction .is .ahout- .1650". F. Simultaneouslyy with ythe -cokeburn-off, theV coke; present ,onnthef-iron. oxide..partielesgelfects asubstantially. completereduction of.v this iron oxide toan iron,compound .ofa-loweroxidation statefcapable of reacting twith water to;liberatehydrogensuch :as particles of .ferrous oxide v(Feo) or particlesof elemental-.iron in nely divided form; vToeifect this operation1.9'5.MSCF/Hr.v (1,000 Standard cubic feet per hour) `ofabsorber-drygasor other hydrocarbon .gas such as -natural gas, .which may bepreheated to atemperature-of about' l200 F., lis-introduced-into reducer25 via line-52 controlled by. valve'z53. At thesetemperatures,`afhydrocarbonfironu.oxide reaction occurs which gives rise to theformation ofz/carbon monoxide, hydrogen, water and elemental iron. T oefyfeet the coke burnoif, 3.81 MSCF/Hr. of air as .the oxygen-containinggas, which also may be preheated to a temperature of about 1200"F., isintroducedxinto the lower portion of reducer-25 vialine '54 controlledby valve 55. By controlling the operation of reducer 25, the'contents ofthe vessel are maintained in such a condition. that .thesolid,.particlesare.hindered from `settling and asuspensionof .thesolid. .particles having leve1f56 is maintained` in the lowerpart ofthevessel.

Above level;56 .is `collected a. producerfgas richglin carbon. `monoxideand hydrogenwhich .is yformed gduring the. iron,.oxide, reduction. Tol.produce highpurity iron from the. reducer, it is `preferable tomaintaina carbon monoxide, to carbondioxide ratio (volume) v.of vgreater thanabout; 1.0 in .the producer gas, such/asfbetween.about 2.5,v and 5.0..A. ratio dabord-.3.0 yis, preferredto.` insure reduction1 .of the.oxides .to4 elemental Hiron. lFor` reduction ,to ferrous. oxide(FeO)`a. ratio offfromuabout 0.5 .to as high as about 3.0- may -be-used.This gas is. introduced into separatorg57 .inwhich tracesfof. suspendedparticles are,.re`moved and returned tothe-high density suspension.phase below level156l 1Frornthe=fupper portion .of separator. l57,.5.39. MSCF/Hrcof-a produeer e gas analyzing about 80% carbonmonoxideisfremoved,aba

temperature of about l650 F. v ia line 58. This producer gas passessubsequently Vthrough heat exchange means .59 whereby it.is.`cooled.,-oonsiderably-.losingi its h eat, in -one modilication ofthis,.invention,;,in indirect ,heat exchange with .thehydrocarbon gas(and air. introduced, as previously described, ,into .reducer'25- ,Theproducer gas is` thus vcooledto a. temperature below `l-,0( ),0 F.y andis .passed byI .means of line60. intoseparatornl wherein-`remainingtraces, 'of suspended solid vparticles are. removed. Tgheseparticles. may. be recovered j yfrom thevproducer gas `ina high-.voltageelectrical .precipitator or ina Specially .designedcentrifugaltypeseparator such asA a cyclone. `-Recovered. .particles maybereturned to(reducer 25 vvia 1ine162. The.v solids-.free.gproducer V gas `isremoved, from. separatorl ,by means. ofline r63;.A andgsa portionof.this.'is..sent via line .64 eontrolled-byyalve 65 forV useas fuel, such`.asin furnace--18a in which the incoming heavyoil feed, recycle'coker-residuum, and hydrogenated residuum .are raised lto Ycolingtemperatures prior to .their introductioninto colierZt). The remainderof the carbon monoxide. gases` pass-vialine 66 forffurther processing.in connection withthe .recovery of elemental. sulfury from .the sulfurdioxide bearing gases. prof duced during the conversion of iron sulfideto `iron oxide, as hereinafter more fully described. The reduced solidsare removed-from reducer 25 via line 112 and a--portion may be passedthrough. line112a controlledbyvalvey 113a directly into..the coker.inwhich part-of the desulfurization may. be effected .at .ook-ingtemperatures.

Meinl. .Sulde oxidation In oxidizer 67, 7;73 tons per day of solidmaterial containing 91% iron sulfide, magnetically separated from thereducing regenerator eli'luent, as hereinafter described, are-introduced-and.,-converted to ironr oxides ('Fe304). Thisreaction is conducted`ata-temperature of .about 1200 F. although .temperatures-as low asabout-l,000 F. to as high asabout 2,000 Fforihigher-.may .be-employed,`.if desired. The -iron sulfide is ,suspended in an air streamintroduced.,bygmeansof line; `6.8 controlled by Valve I 69 `andthegsuspensionv together .with recirculated irontoxide is .passed-viaaline. 70` ,th-rough Wasteheat rboiler 71 wherein.a.portien.of :theheabgeneratedduringo davt-io11-.of| `the. iron suld'e, is, dissipated.inconvertingnwater introducedvia line 831x controlled by valve 82 into.steam whichis removed-from .separator 83 via 4linelflqcontrolled by.yalveS. The suspension `isnthen ,passed Ifrom boiler-7f1 via.flinev72.into oxidizerf-67. A. level-.731 is maintained: in .oxidizer;.67=-belowqwhich iron sulfide-and iron` oxide .particlesarevmaintained, in acondition of hindered. settlingy as. a relatively -h-igh .densitysuspension. The solid particles are removed from oxidizeru67yial-inerf74 controlled1by.fvalve'75andqatportion thereof is returnedvia.1line'.76,.controlled by -valve .77 to'pbere- .combined .with Vthe.incoming` `iron. sulfide, and air; for recirculation through lwasteheatfboilert71. vThequantity offthiswrecycle stream'Y amounts to. aboutf 1;081.tons=.per day,.-although higher, or'lowerf recycle rates. may,be employed, in order; to maintain: f-the-,oxidizer temperatureat .thedesired` value. The. remaining quantity of-oxidized material, .passesvia line T7.8 `controlled; :by valve `"79nto auxiliary reduceitvufat:theY rate of 7.1.tons -per day and has approximately thea yfollowingcomposition:

Within auxiliary reducer S0 4this downwardly `owing solid mixturecontacts a countercurrent streamof gas removed'from reducer25 at a rateoflz4' MSCF/Hr. by means of line 86 controlled by valve 87 and whichcontains carbon monoxide. This countercurrent contact ef- .fetsfasubstantiallyAcompletereduetion-of :the FezOs toPe3Q4,..and.simultaneously; the solids, are heated? to; approximatelythe. temperatureexisting kwithingthe reducer, .that v.-i s,-about165.0921?. ,Tfhe EesOtfthus. produced, c0n tainingabout `8.0% iron...sulfide and `substantially1.10.0 FegQs, isftpasnsedfromauxiliaryfreducer byfmeanslof linegcontrolled. by-valye ,'89 intoreducergl.' :The: -gas removed; .from auxiliary reducen 80. aftercontacting `.the oxidizediron .sulfide from Aoxidizer 167`passes-viaeline 90 ontrolled.byyvalvefllqintooxidizerz,67.

- hin.,ex;i dizer 6.7:athe.i.ironqsuliide:is..oxidizedf.to `a ure-of,iron1-oxides-..;with itheysimultanoous; production yofgases rich inf.sulfur dioxide. .Under-conditions ofthe presentoperation these-gases areremovedgfrom oxidizer .67 gthrough separatory Q2 `by lmeans .of' which*st irspended.v particles of iron oxides are separatedmandreturned -to apoint below level 73. The solid=free sulfur dioxidebearing gases areremovedfrom separator 92 by means of line 93v controlled by valve94 andare introduced into separator'95 which preferably isof the high voltagetype; bymeansV of which remainingtraces ofV very'ne solidsare-precipitated'.v yThe solids'thus recovered may be disposed of orreturned to the system by means of line 96. The sulfur dioxide bearinggases, freefrom .y suspended particles, ,pass fromseparator .95 by.means `of `lir 1e..9'7,.atp.ara-te` of 22,0, MSCF/ .and are combinedwith 14.3 MSCF/Hr. of producersglscontain-` ing .a high concentrationocarbonmonoxide owing through line .6.6.

Sulfur `proeiLlzction The gaseous mixture. thus formed' has atemperature of about 1100 F. andcontains carbon ,monoxide-and sulfur`dioxide underconditionsat which they readily react toproduce-elemen-talsulfur according to thefollowing reaction:

rThis gaseous mixture vis-.cond-uctedby means of line 98 into waste-heatboiler 991'wherein the heat generated is employedltoconvertWatertosteam. =Water is introduced. byifmeans of line controlled byvalveltlland steam formed is removed from separator 102 bymeans of-2line103 controlled by Valve 104. The heat made available by this reaction isabout 300,000 B..-t. u. per hour, a substantial portion of which isrecoverable in the.` form of high pressure steam. Gases areremoved fromboiler 99' at a temperature of about 1185o F. by means of line 105 andare introduced into heat exchange means 106 wherein the gases arepreferably cooled to a temperament-below,about 250 Fplosing their heatin; this modifieation .at.- a -r,ate -of about 500,000 B.. t..-,u.

per hour in the generation of steam. Sulfur is hereby precipitated insolid form and liquid sulfur may be recovered, if desired, bymaintaining the temperature above 250 F. such as for example, at least300 F. This gas in introduced via line 107 into separator 108 wherelnthe sulfur is separated. Sulfur is thus produced at a rate of about 1.8tons per day and is removed from separator 108 via line 109. The sulfurthus produced 1s of high purity. The solid sulfur is in a nely dividedform suitable for a wide variety of uses, especially fruit tree dusting.

The reaction of carbon monoxide and sulfur dioxide does not go tocompletion so that the gases removed from separator 108 by means of line110 are contaminated with unreacted quantities of sulfur dioxide andsmall quantities of hydrogen sulfide formed through the reaction ofsulfur dioxide with water vapor. In order to recover these quantities ofsulfur, the gas removed from separator 108 via line 110 controlled byvalve 111 is employed at a rate of about 34.2 MSCF/Hr. to convey andsimultaneously to cool the iron etiluent removed from reducer 2S at arate of 26.2 tons per day by means of line 112 controlled by valve 113.These solids are removed from reducer 25 at a temperature of about 1650F. and

have approximately the following Weight composition: Constituent: Weightper cent Iron 49.5 Iron oxide (FeO) 17. Iron oxide (Fe3O4) 9.9 Ironsulfide 21.3 Chloride 2.3

In doing this an etiicient contact of the residual sulfurbearing gaseswith iron is effected substantially completely converting the sulfur tononvolatile metal compounds such as iron sulfide. The metal sulfurcompounds are recirculated through the system for reprocessing andpermit the discharge to the atmosphere of gases substantiallyuncontaminated with sulfur and a substantially complete sulfur recovery.The gaseous suspension thus formed passes by means of line 114 intoseparator 115 wherein the solids, comprising a mixture of iron oxide andiron sulfur compounds together with iron, are separated from the heatedgases. The solids thus conveyed and cooled are removed from separator115 at a rate of about 26.7 tons per day at a temperature of about 825F. These solids have approximately the following composition:

Gases are removed from separator 115 at a temperature of 825 F. via line116 having a substantially reduced sulfur content.

The solid material containing recovered iron sulfur compounds removedfrom separator 115 passes via line 117 and may be quenched by directcontact with about 80 tons per day of water introduced by means of line118 controlled by valve 119. The temperature is thus reduced to about150 F. and 190,000 B. t. u. per hour of heat are recovered. The slurryof solids in water pass via line 120 into primary magnetic separator 121wherein a substantially complete separation of iron sullides iseffected. The elemental iron and iron oxides thus recovered is removedfrom separator 121 via line 122 controlled by valve 123 at a rate of25.1 tons per day. The stream has approximately the followingcomposition:

This slurry of iron and water is combined With 212 barrels per day ofcoker distillate removed from the 8 lower outlet of absorber 41 andflowing through lines 48 and 50a controlled by valve 51. This materialis subsequently passed by means of line 124 to the hydrogenation step ofthe process which will subsequently be described.

Also removed from magnetic separator 121 is a stream of the relativelynonmagnetic materials containing substantially all of the iron sulfide,and some iron oxide, the chlorides, and the like. This material isremoved by means of line 125 controlled by valve 126 and is introducedinto secondary magnetic separator 127 wherein a separation of the ashand chlorides is effected from the iron oxides and iron suldes. The ashand chlorides and other nonmagnetic materials are removed by means ofline 128 controlled by valve 129 and are discarded. The iron sulfideconcentrate is removed by means of line 130 controlled by valve 131 at arate of about 10.2 tons -per day and has approximately the followingcomposition: y

This material passes by means of line 132 and is combined with a largevolume of gases removed from separator 11S via line 116 at a temperatureof about 825 F. This gas is again employed to convey solid materials andsimultaneously to remove last traces of sulfur compounds. Water isevaporated to form a completely gaseous suspension of iron sulde and asmall quantity of iron oxide (FesOt) and the suspension is passed bymeans of line 133 into separator 134 at a temperature of about 425 F.Within separator 134, suspended particles of FeS and Fe3O4 are removedfrom the suspended gas. These are passed by means of line 135 controlledby valve 136 at a rate of 7.7 tons per day to be combined with air forintroduction into oxidizer 67. The sulfur-free gases are discharged tothe atmosphere by means of line 137 at a rate of about 34 MSCF/Hr. Asubstantially complete sulfur recovery as elemental sulfur may beeffected in this manner.

H ydrogenaton Returning now to the actual hydrogenation step, the cokerdistillate owing through line 50 at 212 barrel per day rate is combinedin line 124 with 25.1 tons per day of a slurry of iron and water formedas described above. The slurry passes via line 124 into mixer 138 towhich additional water may be added by means of line 139 controlled byvalve 140, if desired. With this additional water may be addedwater-soluble salts of various types which enhance the hydrogenationreaction or these hydrogenation accelerators may be added, if desired,directly to the hydrogenation reactor. Hydrogenation acceleratorsapplicable in this respect are the water-soluble halides of metals suchas calcium, magnesium, iron, manganese, and the like, as well as thehalides of ammonium.

The slurry prepared in mixer 138 passes by means of line 144 into highpressure pump 142 by means of which the slurry is compressed to apressure which approximates that required in the ultimate hydrogenationreaction. This slurry is passed under high pressure through line 143 ata rate of 59.6 tons per day controlled by valve 144 into heater 145.Material introduced into heater 145 has the following weightcomposition:

In other operations, the composition may be varied to obtain differentdegrees of hydrogenation. From 5% to 35% iron, or ferrous oxide, 2% to25% water, and 30% to 90% oil may be employed, for example.

This material is removed from heater 145 by means of line 146 controlledby valve 147 and is introduced at a temperature between about 500 F. and1200 F. into 9 hydro'g'eatien reactor-148i In fths particular operador-atemperature of about 750 F. was employed in the hydrogenation o'f-th'ecokerf' distillate.' Hydrogenation'reactor 148 is provided`withv'a'gitator149and` driving -mean's v-150 whereby"the` contents ofthe-'reactor are maintained 'in' a condition of -thorough agitationduring'the entire reaction".

It yis` sometimes desirable; where heating of the combinedhydrogenatio'n reactorfeed lis not feasible, to separately heat the oilcontaining the suspended iron in one stream and the water which maycontainfa 'dissolved hydrogen accelerator in"the-oth`er. In'thismodification, the magnetic separation is effected' in the' absence ofwater. The water is ithen introduced at high `pressurevia ylinei119athroughla separatecoil-in heater ,145 at a rate controlled by valve150cv directly into reactor .148. The temperature may be above'o'r`below that of 'the inlet oil stream and may in some instances be atpressure and-temperature conditions above the critical. Suchan'operationpermits the complete iron-steam reaction yforhydrogenproduction to `take placeunder'the conditions best suited forhydrogenation. A veryieffective utilization of the hydrogen thus formedis effected;

The pressure under whichl the hydrogenation reaction isaccomplished isabove atmospheric ranging as high as 115,000 pounds per square inchVV(1,000 atmospheres). Lower pressures-may 'be employed 'such as lesslthan about 10U-pounds per'square inch, although in the hydrogenationvofsuch material as Coker distillate'obtained from Santa Maria Valleycrude petroleum; pressures in the range of from 3000 to' 9000 pounds persquare inch are desirable.-

During-itsV passage through `hydrogenation reactor 148 the mixture ofirony-water and cokerdistillatereacts for the conversion oftheunsaturated 'hydrocarbon 4constituents of the coker distillate ytosaturated or paraffinicfractions, the-destructive hydrogenation of thehigher molecular weight and higher boiling-hydrocarbon constituents forthe production ofl saturated hydrocarbons boiling in the lowertemperatureranges, the destruction of nitrogen, oxygen andsulfur-containing hydrocarbon compounds with the formation of ammonia;water, and hydrogen sulfide, respectively, and substantially completelyhydrogenated remnants of these` constituents, the conversion of the-ironandI FeO through reaction `with water to higher oxides 'of iron such asFe304 with the simultaneous production of vhydrogen which'is employedsubstantially* as it is formed vin 'the aforementioned hydrogenationreactions, and the conversion of a portion ofthe iron or iron oxides tosulides of iron through reaction withy hydrogen sulfide or with thesulfur-'containinghydrocarbon compounds.

The heterogeneous mixture of solids and'liquids coni taining dissolvedgases'fis removed from hydrogenation reactor 148 by means of line151controlled byva1ve'\152. A' portion'of the hydrogenationfreactor'eiuentEth'us removed may fberecycled through heater 145' via line 151:1controlled by `valve 152a4 bycirculation purrip1-153a.v In thi'smannerthe'entir'e system; heater andreactor', may operate under 'substantially:isothermal conditionsfsoy that hydrogen generated Vby reacting ironwithwater vis'formed at' the hydrogenation temperature permitting a'vsubstantially complete utilization as formed. Sucha'mixing of aportion'of fthe hydrogenated effluent with the-feed lto the reactorpermits quickheating and avoidsV thecondition encountered wherebyvthehydrogen is generated attempe'ratures duringrheating which4 are not`sufli'ciently `high to effect the desired degree'of hydrogenation.

Theremaining portionof the reactor efuent is' intro; duced into thelcentral lower portion of hydrogenation effluent bubble tower 153'.Inthis'fractionating column, xthe hydrogenation reactor efue'nt isseparatedZ into its'fcon'- stituent parts. Anoverhead vapor-passes bymeans of line 154 into" condenser 155 wherein 'a partial condensation'ofvthe lower Iboiling constituents is effected; This cooled productpasses' by means of line 156'into separator 157 fromwhich'the gasesareremoved by means ofline 158 controlled by valve 159 which alsomaintains aback pressure on'the'column: The gasthus obtaineclrmaycontain a certain amount of hydrogen 'asA well,` asthe normally gaseoushydrocarbon constituents. This gas'rnay be'employed `ase fuel the`processyor may 'be sent `to` storage-or further' processing'.facilitiesAnotfshown.- The condensateis removed :from separator 157 via line' I160controlled `by valve '161 anda-portion is-returned -tozthe upper part of`tlierbubbletower by meansy of line `1621as 10 ferrer; Whsetheir-,maintiens cpfea'ud rhrugniiiie its at a rat'eoff55barrelsiperday-control-ledfbyI vali/e164; This-liquid fraction 'ic'o'r'nprises'a'Vvhyd'r'od'es'ulfuriz'ed Agasoline which is substantially frees-fromnitrogen andsulfur contamination; The A'gasoline may` be blended5 in any`desirable proportion with -unsat'ura'ted hydrocarbon fractions obtained"from the'-coker "gasoline *product* produced from the lupper'portio'nofcokz'e'r'bubble tower 290", previousiy-"d'escribedi l Theeondi'tions:of tem'p'erat'ureandpressuref'whiih 'are employed-4inTthe-'hydr'ogenation 'ste'p of -theprocess Emay lb'e'"modified byl"theiincorporationoffcatalytic-'quantities lof such; hydrogenationand/or -de`sulfurization catalystsa's nickefand cobalt oxides-lorVAsuldes. Molybdenum or -tungstenoXides--or sultides-may als'obeemployed.' To en'- hance de sulfurization, catalysts `sc'has' coba'itmolybdat'egco'balt chromafe,' and the 'corresponding-nickel compoundsmay-'beint'roducedwith the-mixtureofwater, oil, and iro'n-or'ferrous'oxide-intothe`hydrogenation reactor'. Thcobalt' and nickel-oxidesandsulfdes-are especially-applicable'since ithese" compounds 'are' readilyregenerated under the'iexistin'gl conditions' of Y.operationv lin whichfthe oxide'sf'of ironarereduced. BySemploying-catalytic quantities ofthese compounds in the' hydrogenation' reactor, considerable reductionsA"iir temperature andV 'p'r'e'ssurere-` suit: Those J'pre'ssures andtemperatures in thelowerpart off'the'i-ange's given' above permit good'conversionsthat is, temperatures between about 700 i12-.and 800 F.andpressu'r'es of less 'than about .'5000 pounds lIper squareinch;

Ammonia is produced' during-the destructivez'hydrogenati'on ofvnitrogen-containing hydrocarbons. Inv order to eftectanl efficient'recovery of this compound,the' reflux temperaturel of `bubble `tower'153 `-may `be'maintainedat about 210 F1 under atmosphericpressure-operation whereby 'a substantiallyy completefrecovery of`unrea'cted watercontainingdissolved ammonia may be effected bycontinuouslyfdrawing' of'this 'commodity from ktray 165 through`line-166 controlledby valve 167. A hydrodesulfurized"gasoil 'havingf a,boiling zrange `of'ifrom about 200 F. to'-a'bout` 800 F.maybeuremoved,iifdesired, fromthemiddle portion of'colurnn'153 vialine168'controlledby'va'lve 169. This commodity is produced at a rate of 157barrels per day. i.

r-l."he"bottom"part of column 153 '.isumaintained at va temperature'cfbetween"700"' F. and 11000" F. and a small `quantity of hydrogenatedresiduumis *removedV via line 170. AAportionfof this is recycled 4bymeans of line *171fcontro1led by valve 17.2 to a point-somewhat abovethey inlet fof thematerial removed fromy hydrogenator 148. The-quantityof this'residuum amounts to'49 barreis-iper day.v This lmaterial has thefollowing weight composition:I Constituent: Weight'pe'r cnt Hydrogenatedresiduuml FCS i,

100.0 The mteriar is freercuiatdby means offiiii ,1e-figabubbleftower"1"53"I to' be" combined with' the' Santa Maria' Valleycrude" oil :passing with the fcoker bubble@ tower residuumvialine"18"into` heater18` completing the According fto thejm'c'yJrdiication o f 4thejprocessy jof'this in'ient'ion, yas abovedescribed; an l eiientV econorr'iical arid-eas`ilyico'ritrolled processffor the -substantially coinplete'l -con'version )ofy thigh" densityoils' in'tofi desirable 'hydrocarbon. 'fractions of flower density "andlo'wr boiling rangerisprovided.L Furthermoreg'fthe products which areobtained ythrough application offthel processare substantially-'freefrom undesirable nitrogen, oxygen'and sulfur compound contamination andprovide highly` desirable rawmaterials for the formulation l'ofinternal; combustion engine fuels suchl als ga'sygaso'line,v dieselfuel, andl the like;y and vmayalso 'provide suitable stocks for theprepartimiof'high' quality'. lubricating oils and .greasesL4 etc?,ythese "conditions are notu to 'be' osidered limita ingI since y`acertain:latitude'foffvari f'oii7 is permissible" wherebygthelde'sirabl'e'fresults `may bebbtained.' It lis to "be" furtherunderstood' that although the 'high density foil" treated in the abovedescription was a high density crude petroleum having an A. P. I.gravity of between 10.0 and 12.0, other high density oils may besimilarly treated and the same desirable results effected.

The operation of the reducer may be varied such as by altering thetemperature and the carbon monoxide concentration to form ferrous oxide,FeO, in preference to elemental iron. This then may be reacted withwater to yield the hydrogen required in the hydrogenation step. The useof ferrous oxide instead of elemental iron has been found to be ofadvantage, since under some conditions of operation, such as in thehigher temperature range, there is no tendency for the ferrous oxide tosinter or agglomerate or otherwise to form larger particles at theexpense of the smaller particles and reduce the active surface of thematerial.

In another modification of the process of this invention, liuidizedoperations are also performed in the coking of the oil feed in thepresence of coker residuum and hydrogenated residuum, in the oxidationof iron sulfide to iron oxide to form sulfur dioxide and in thereduction of iron oxide to iron in which latter step the coke laid downon the iron oxide during the coking operation is removed by combustionwith the formation of a gas rich in carbon monoxide similar to thepreferred process described above. Herein the oxidizing regenerator mayproduce sulfur dioxide or elemental sulfur depending on oxidizingconditions.

In this modification the high gravity oil such as crude oil, shale oil,tar sand oil, coal oil, residuums, and the like, is combined with ahydrogenated residuum containing suspended particles of iron sulfide andiron oxide. The stream is then combined with a stream of iron oxide(Fe3O4 predominantly) and is passed preferably through a fired heaterwhere the temperature is raised to between about 700 F. and l200 F. toinitiate a thermal pyrolysis. The heated material is then introducedinto a fluidized coking vessel. In the coking vessel, thermal pyrolysisof the heated combined oil streams is effected in the presence ofsuspended particles of iron oxides and iron sulfides. A level ismaintained within the coking vessel below which the heated particles ofiron oxides and iron sulfides are maintained in a condition of hinderedsettling wherein the coke resulting from the thermal pyrolysis reactionis deposited on the suspended solid particles. Above this levelaccumulate the pyrolysis products comprising hydrocarbons in the vaporphase. These hydrocarbons pass through a separator present in the upperportion of the coking Vessel wherein small quantities of suspendedparticles are separated and returned to the r lower portion of thecoking vessel below the level of solid particles. The solid-freepyrolysis product comprising hydrogen and saturated and unsaturatedhydrocarbons having boiling points as high as about 800 F.

and higher are removed from the separator and introduced into a cokerbubble tower where fractionation of the hydrocarbons thus produced iseffected.

In the coker bubble tower and overhead gas product containing hydrogen,methane, saturated and unsaturated C2 and some C3 hydrocarbons areproduced. Condensation of a portion of the vapor removed from the upperportion of the column forms a coker gasoline having a boiling range fromabout 70 F. to as high as about 400 F. The end point of this cokergasoline may be varied by varying the overhead product temperatures ofthe coker bubble tower. A coker gas oil may be removed from the cokerbubble tower at a point intermediate between the pyrolysis product inletand the overhead vapor outlet. This product contains saturated andunsaturated hydrocarbons boiling in the range of from about 300 F. to ashigh as about 800 F., the actual boiling range depending upon variableoperating conditions of the column. From the bottom of the coker bubbletower, a coker residuum is removed which may be recirculated andcombined with a feed stream and reintroduced into the coking vessel forreprocessing. This residuum may also be employed as a raw material forroad-building hydrocarbons such as road oil, asphalt, and the like.

If desired, the coker gasoline and coker gas oil may be combined to forma coker distillate which is hydrogenated for the formation ofdesulfurized and saturated hydrocarbons suitable for internal combustionand engine fuels, lubricating oils and greases. If desired, thesestreams may also be treated individually by hydrogenation as will besubsequently described, or by other processes.

Returning now to the coking vessel, a stream is removed from below thelevel maintained in the coking vessel which comprises coke-ladenparticles of iron oxide (Fe3O4 predominantly), and iron sulfide. Thismaterial is suspended in a gas, if desired, or is otherwise directlyintroduced into a fluidized reducing regenerator.

The reducing regenerator effects the combustion of carbonaceousmaterials such as coke present on the iron oxide and iron suldeparticles, and also effects a substantially complete reduction of theFe3O4 to finely divided elemental iron or to lower iron oxides such asFeO. The temperature of operation at which the reducing regeneratoreffects these conversions may be between about l000 F. and 2000 F., atemperature of about 1650D F. being typical. An oxygen-containing gassuch as air is introduced directly into the reducing regenerator incontrolled quantities to effect coke combustion which favors theformation of carbon monoxide and liberates heat aiding the iron oxidereduction. Introduced at a separate point in the reducing regenerator isa gas containing hydrocarbon and/or carbon monoxide such as natural gas,producer gas, or mixtures and the like, which assists the reduction ofoxides of iron to lower oxides or elemental iron. These gases, theoxygen-containing gas, and the producer gas or natural gas arepreferably introduced below the level of suspended solids maintained ina fiuidized state in the reducing regenerator. It is also to bepreferred that a portion of these suspended solids be continuouslyremoved, passed through suitable heat exchange means, and reintroducedin a closed cycle to maintain temperature control of the reaction.

In the reducing regenerator conditions are controlled so that the gasesproduced during the reaction contain hydrogen and water vapor in a ratioof about 2.0 and carbon monoxide and carbon dioxide in a ratio of atleast 3.0. Under a pressure of operation which may range from nearatmospheric to a high as several hundred pounds per square inch andunder the conditions of temperatures disclosed above the production of agas containing the constituents recited in the ratios given insure asubstantially complete conversion of coke and of the iron oxideintroduced into the reducing regenerator to finely divided elementaliron. A stream consisting of iron and iron sulfide essentially, and alsocontaining small quantities of iron oxide is continuously removed fromthe reducing regenerator and subjected to a magnetic separation whereinthe iron and the other materials with high magnetic susceptibility areseparated from the iron sulfide. The iron thus recovered is employed inthe hydrogenation of the coker distillate.

The iron sulfide recovered from the magnetic separator is combined withair and continuously introduced into an oxidizing regenerator in whichthe oxidation of iron sulfide to iron oxide is conducted underconditions suitable for maintaining the solids in a state of hinderedsettling and at a temperature of from 1000 F. to as high as 2000 F. Inthe oxidizing regenerator a suspension of solids is maintained in whicha level of liuidized soligds is present. In the upper portion of theoxidizing regenerator the gases produced in the oxidation reaction arepassed through a centrifugal separator for the removal of suspendedsolid particles. Suspended solid-free gases are subsequently removedfrom the separator containing sul-fur dioxide or elemental sulfurdepending upon the conditions of operation, Elemental sulfur in liquidor solid form may be produced in the system by operating with a minimumquantity of air required in the iron sulfide oxidation and bycontrolling the effluent gas temperature so that at least part of theiron sulfide is converted to iron oxide and sulfur. In this modificationthe iron oxide formed from the iron sulfide oxidation is continuouslyremoved from the oxidizing regenerator, cooled, and combined with thehydrocarbon feed to be coked and is introduced therewith through theheater into the iiuidized coking vessel.

As indicated above, the stream of solids removed from the reducingregenerator is magnetically treated to recover a concentrate ofelemental iron. This is mixed to form a slurry with at least part of thehydrocarbons obtained from the coker bubble tower and with water. Theactual quantities of iron and water in relation to the amount of oil tobe hydrogenated have been set forth above and are dependent upon thequantity of olefinic or comme .13 otherwise'unsaturated:hydrocarbonswhichl are'. desirably converted to.paraiiinicorfsaturated compounds. Under the1conditions of-the`hydrogenation, iron'reacts'fwith Water withthe formationof iron oxide.and the liberation of hydrogen according to 'the following reactionnThis reaction supplies-hydrogen required in the. hydrogenation reactionandis consumed substantially as it is formed. The quantity of iron andwater is selected to .provide `sufficient hydrogen to1 effect theidesired degree of hydrogenation.

lt is desirable to assist the hydrogenation reaction and the hydrogengeneration by the addition' tol the. slurry of halides of `ammonia or"various metals such .as iron, manganese, magnesium, calcium, and. thelike, which function as accelerators.

The slurry, containing the .constituents above'described, is pumpedlthrough a .means for heating wherebyV temperatures from about500 F'.toiabout `1200.o `F-.or more are developedinthe system. Theheatedoilis-Y introduced thereby into a hydrogenation reactor-at apressure as high as about 15,000 poundssperrsquare inch. This'vessel ispreferablycontinuously agitated to permit uniform suspension ofthereactingsolids 'inf the liquid and to assist'temperature control.Water, heated and .under pressure, may be added separately fromtheoili'andiron, or the slurry maybe combined witha part of the yhotreactor eiiiuent and introduced intothe reactor.

In the hydrogenation reactor, sulfur-containing;hy drocarbonconstituents are decomposed'presumably by destructivehydrogenationwiththe :formation of hydrogen suliideand the hydrocarbonremnant of the :sulfurcom pound. The hydrogen suliide ultimately reactsWitheither theiron or the iron oxides present forming iron sulfide inthe system.. Nitrogen-containing hydrocarbon :compounds are similarlydecomposed forming ammonia. The hydrogenator eiiuent containing theabove indicated constituents is subsequently passed fromy thehydrogenation reactor to a means for effecting the separationof thevarious constituents. inthe preferred modification this means forseparation may comprise a` distillation column from which gaseoushydrocarbons are removed together with hydrogenation hydrocarbonfractions, gas oil fractions and others. Provision is preferably made in.the distillation columnfor the removal of water containing dissolvedammonia which may be substantiallycompletely recovered by this means.Fromthe "lowest part of the distillation column .a hydrogenated residueof higher boiling hydrocarbons is-.removed which contains suspended`solids including iron oxide, iron sulde, and possibly some unreactediron. This residuumi may be magnetically separatedfforthe recovery ofsolid particles, or in the preferred modication is. combined in itsentirety with the heavy oil to be hydrogenated and is returned with thatsteam to the coking vessel for retreatment.

In accordance with this modification a high density oil -is'subjected toconditions of thermal pyrolysis and destructive hydrogenation wherebyvasubstantially complete conversion to .hydrocarbon fractions to moredesirable boiling range is eifected. By-products, including ammonia,sulfur dioxide, sulfur, and possibly various suldes and oxides of ironmay be produced. if desired. One outstanding feature of this process isthe fact that a high pressure hydrogenation may be effected in thelcomplete .absence ofthe extensive gas compression facilities normallyrequired in high pressure hydrogenation operations and also intheabsence of an expensive and often easily poisoned hydrogenationcatalyst. Another advantage of this modification comprises the use ofthe magnetic separating means for the control of `iron sulde byseparating this material continuously and converting it by oxidation toiron oxide. This eliminates recycling of iron sulfide uselessly throughthe process.

In an additional modification of the process according to thisinvention, a iiuidized Coker, a fluidized `oxidizing regenerator and aiiuidized reducing .regenerator are also employed. In this particularoperation the heavyhydrocarbon stream to be treated is combined withl ahydrogenated residuum containing iron oxide and iron sulde and With acoker residuum and introduced viaa iired heater into 'the-coking vessel.The oxidizing regenerator is so positioned with respect toith'evcokerthat iron oxide withdrawn from the oxidizing .regeneratoriwis combinedwith the .heated'hydrocarbon stream fromtthe heaterand '1?1 thezztwo:ares introduced: simultaneously into ..thef:cok"' g vessel. In thismanner a substantial utilizationivof'the'` sensible'lheatV of .ironoxide 'from the oxidizingLrege'nerator is.'.utilized inicausing..thermal pyrolysis. ofl the heavy oil beingcoked. Also in :this manneriront` oxideffromthe oxidizingi regenerator is passed. through the icokingvessel and` alayer1of coke .is `depositedzuponV each particle.-The hydrocarbon stream from- 'theheater maybe vatautemperature ofbetweenaabout 700 F. and.. l200 F.v :and

' bubble tray typewhereinvarious hydrocarbon. fractions,

gaseous and liquid, are separated from one'. another. During coking, acertain .quantity'of'hydrogen suliide'is generally formedfrom. thedecomposition of -sulfurfcontaining."hydrocarboniconstituents Thismateriallis removed-v together With the/hydrogen, C1 and C2 saturatedandy unsaturated.hydrocarbons from the upper portion of the column.Infone modificationlof this invention, the gas thusproduce'd issubjectedito a-treatment adaptable-to removing the hydrogen. suld'e thuscontained-such-as vby absorptionlin basically reacting adsorbentssuch asaqueous solutions of alkali metalf salts,A absorptionin solutions'oforganic compounds'such as ethanola'mines, andthe like. The hydrogensulfide-free hydrocarbon gases areintroduced into the reducingregenerator to-eifect the reduction of iron oxide to finely dividedmetallic iron as` 'sub sequently described.'

The normally lliquid `portion of the hydrocarbons `in the 'pyrolysisproduct are further fractionatedin'they coker bubble vtower to"produceacoker distillate or coker gasolineeboiling from about F. to 400 F. andacoker gas oil boiling from about 350 F. to about 760 F. These individualvfractions may beproduced and sent'to storage, individuallyhydrogenatedaccording to the process of this=invention,.or produced from the bubbletower'as a single coker distillate streamthe total quantity-ofwhich is'then hydrogenated. s

Fronrthe lowestportion of the coker bubble toweris removed a Cokerresiduum consisting ofthe higher boiling hydrocarbons whichmay beemployed as fuel oil, road oil, in the preparationof asphalticroad-building material, and the like. This residuum inthe 'presentinvention is preferably combined with'the hydrogenated residuum and withthe high density oil to be treated and the combined stream isintroducedinto the coker for pyrolysis.

From the lower portion of the coking vessel is removed a stream ofiinely divided solids comprising a mixture of iron oxide, iron sulde andcoke. In this modiiication of the invention a minor portion such as fromabout 10% to 50% by weight of the stream is suspended in air orotheroxygen-containing gas'and introduced at a temperature of about S50 F.into the oxidizing regenerator. Preferably aboutone-third of the streamWithdrawn from the Coker is thus treated.. Within the oxidizingregenerator, which may operate from .a temperatureof about 1000 F. to2000 F. and preferably at about 1200" F. to l500 F. the coke is burnedto carbon monoxide and carbon dioxider and the iron sulde is oxidized toform sulfur dioxide and the higher iron oxides. This reaction isconducted in the oxidizing regenerator in the presence offluidized-solids whereby a level is maintained Within the Vessel. Frombelow this level -and from that part occupied by the suspended solids isremoved a continuous stream of solids consisting predominantly of thehigher. iron oxides at a temperature of about l700 F. A portion ofthis-is combined with the higher iron oxide, iron sulfide and cokeremoved from the coking vessel and recirculated to the oxidizingregenerator to effect temperature control. The remaining quantity isintroduced directly into thecoker Where a carbonaceousideposit of cokeis laid down onthe particle yto permit ironoxide reductionand-aportionof which is converted to iron sulfide and treated as justabove described.

The remaining portion of iron oxide, iron sulfide and coke removed fromthe coker comprises the major portion of the stream from about 50% toabout 90% by weight is introduced into the reducing regenerator whichmay operate at a temperature of about 1400 F. and 1800 F. Intransporting this fraction of solids removed from the coker to thereducing regenerator the solids may be suspended in a hydrocarbon gas ora producer gas and introduced as a fuidized system into the reducingregenerator. Within the reducing regenerator at a temperature of aboutl750 F. iron oxide is actively reduced to elemental iron by the actionof hydrocarbon gas which may contain considerable quantities of methaneand ethane and may, if desired, comprise desulfurized gas produced asthe lightest product from the coker bubble tower as previouslydescribed. The operation of the reducing regenerator is preferably suchthat the gas produced therein contains carbon monoxide and carbondioxide in a molar ratio of about 3.0 or more and hydrogen and watervapor in a ratio of preferably 2.0 or more. A level of fiuidized solidsis maintained within the reducing regenerator from above which gasesproduced in the production reaction are withdrawn. From below this levelis withdrawn a stream of solids comprising finely divided iron.

The gas removed from the upper portion of the reducing regeneratorpasses through a separator wherein it is free from suspended solids andthe solid-free gas comprises a producer gas containing substantialquantities of carbon monoxide and hydrogen. This gas may be employed asfuel, as a source of hydrogen, or with a moderate amount of purificationas a source of a mixture of carbon monoxide and hydrogen which may beemployed as a synthesis in a catalytic carbon monoxide hydrogenationconversion for the production of synthetic organic chemicals and liquidfuels. Such catalytic conversions are typified by the l. G.Bergiusprocess and the Fischer-Tropsch process.

A stream of finely divided iron containing some iron oxides is removedfrom the lower portion of the reducing regenerator and a part of thisstream is recirculated with the material introduced into the reducingregenerator in order to maintain temperature control. The remainingportion is cooled such as by passing through a waste heat boiler and issubjected to a magnetic separation or other separatoin wherein a streamof substantially pure elemental iron particles is recovered. Thenonmagnetic material may be returned to the process for retreatmentsince an appreciable quantity of this may comprise oxides and sulfidesof iron of relatively lower magnetic susceptibility. The finely dividediron is introduced at a controlled rate into a mixer which is also addeda controlled quantity of water and at least part of the coker distillatehydrocarbons obtained as products from the coker bubble tower. A slurryof this material is prepared in the mixer in which the ratio of iron towater is such that under conditions in the hydrogenation reaction ironwill react with the water to produce a sufiicient quantity of hydrogento hydrogenate to the desired extent the unsaturated olefinic andaromatic hydrocarbon constituents present in the coker distillate. Thismaterial is removed from the mixer by means of a high pressure pump andpassed through a heater capable of quickly increasing the temperature ofthe slurry to between about 500 F. and 1200 F. depending upon the natureof the coker distillate and the type and severity of hydrogenationdesired. Temperatures of the order of 700 F. to 850 F. are suitable formoderate hydrogenation of olefinic constituents while temperatures inthe upper portion of the range such as from 850 F. to 1100 F. are welladapted to effect cracking in the presence of hydrogen in which case athermal decomposition of the hydrocarbons in the coker distillate iseffected accompanied by immediate hydrogenation of the hydrogenfragments formed.

The hydrogenation operation is preferably carried out atsuperatmospheric pressures which, for example, may be as high as 1000atmospheres or 15,000 pounds per square inch. Suitable operatingpressures for the hydrogenation reaction may run lower than this maximumsuch as between about 250 pounds per square inch and 7000 pounds persquare inch. Under these conditions of pressure and temperature thehydrogenation not only saturates the unsaturated hydrocarbonconstituents present, but also decomposes sulfur, nitrogen and oxygenderivatives of hydrocarbons with the formation of hydrogen suled,ammonia, and water, respectively. The hydrogen sulfide, at least inpart, is found in the hydrogenation reactor efliuent as iron sulfide,While the ammonia formed accumulates in the unreacted water phase. Thehydrogenation reactor is preferably provided with means for maintaininga continuous and eicient agitation of the contents of the vessel inorder to insure uniform treatment and to prevent settling of the solidscontained in the system.

The hydrogenation reactor effluent comprises a hydrogenated oil phase,unreacted water and solid particles comprising iron oxide, iron sulfide,and possibly some unreacted elemental iron. This entire material isintroduced into a hydrogenated product bubble tower or other means ofseparation in which the hydrocarbon phase of the hydrogenator effluentis fractionated into portions having any desired boiling range.Depending upon the severity of the hydrogenation conditions, a variablequantity of gas containing saturated hydrocarbon gases may be produced.This gas is removed from the bubble tower as an overhead product,cooled, and the normally gaseous constituents are separated from thecondensate. This condensate comprises a hydrodesulfurized gasoline, aportion of which is returned to the bubble tower as reflux while thercmainder is produced from the column as a gasoline product. Alsoremoved from the column is an aqueous phase containing ammoniumhydroxide. A gas oil product may be also produced which may have aboiling range from about 400 F. to 800 F. The higher boiling hydrocarbonconstituents are produced as a hydrogenated residuum from the lower partof the bubble tower and carry with it iron oxide and iron sulfide formedfrom the elemental iron during the hydrogenation reaction. This residuumis preferably treated to recover the iron compounds and may be combinedwith the heavy oil as feed stock to the process and returned therewithto the coking vessel.

This modification of the process, according to this invention permits asubstantially complete conversion of low value high density oils todesirable hydrocarbon fractions uncontaminated by sulfur having lowerboiling ranges and suitable for internal combustion engine fuels or asfeed stock in the preparation of high quality lubricating oils andlubricating greases. The usual hydrogen compression facilities and theexpensive sensitive catalyst together with some hydrogenation processesare hereby eliminated.

In the foregoing modifications of the process of this invention it hasbeen found desirable, particularly in those cases when heavy or viscoushydrogenated residuums are formed which carry suspended solid particles,to convey a diluent oil into the hydrogenator bubble tower to assist inconveying this residuum. Recycling the coker bubble residuum as thehydrogenated residuum diluent has been found effective. Generally, thequantity of hydrogenated residuum is not large and not sufficient tocarry the amount of solids present,

Another modification of the process of this invention exists in which asubstantially complete vaporization of the hydrogenated effluent iseffected to permit quick separation of the solid particles from theproduct.

A high density oil such as low A. P. I, gravity crude petroleum iscombined with a coker bubble tower residue and with a hydrogenatedresiduum containing a small quantity of iron oxide particles and themixture is heated to a temperature between about 700 F. and l200 F. andintroduced into the coking reactor. Higher iron oxide such as FesO4 andFezOa produced from iron sulfide in the oxidizing regenerator is alsointroduced into the coking reactor in which the deposit of coke is laiddown on the particles. Lower molecular weight unsaturated hydrocarbonfractions are simultaneously formed. The hydrocarbons thus produced arefractionated in a coker bubble tower with the production of gas, cokergasoline, and coker gas oil. The coker distillate is employed as feedstock to the hydrogenation unit and includes the gasoline, gas oil, andother fractions.

The coke-laden iron oxide passes from the coking vessel to the reducingregenerator into which air and part of the gas produced from the cokerbubble tower are introduced. The reducing regenerator is a vessel inwhich a fluidized suspension of solids is maintained with the existenceof a level of solids below which carbon oxidation and carbon reductionreactions are effected. A stream of iron particles substantially free ofcarbon and containing iron sulfide, ash and sodium chloride in minoramounts, is removed. The gas produced from the upper portion of thereducing regenerator contains a high concentration of carbon monoxideand also contains hydrogen and comprises a suitable producer gas whichmay be used as fuel or in the conversion of hydrogen sulfide or sulfurdioxide to elemental sulfur in a suitable reactor.

This stream of solid particles removed from the reducing regenerator isdivided into two fractions, the major proportion of which is combinedwith the proper quantities of coker distillate and with water forintroduction into the hydrogenation step of the process. The minorfraction is subjected to the action of the magnetic separator by meansof which the ash and sodium chloride contents are separated from theiron compounds. The ash and salt-free matter obtained in the magneticseparator is combined with the major portion referred to previously andemployed in the hydrogenation reaction.

A slurry is prepared containing coker distillate, water, and iron in theproper proportions so that the reaction of iron with water will producea quantity of hydrogen sufficient to effect the desired degree of cokerdistillate hydrogenation. This slurry is picked up by a high pressuremultistage pump and is passed together with additional water, ifdesired, at a controlled rate through a heater capable of raising thetemperature of this mixture to between about 500 F. and about l200 F.For the hydrogenation of a coker distillate prepared from a low A. P. l.gravity crude petroleum such as that obtained from the Santa MariaValley of California, a hydrogenation temperature of about 700 F. to 800F. is desirable and a pressure of about 5000 to 7000 pounds per squareinch although pressures as high as about 1000 atmospheres or 15,000pounds per square inch may be used.

The heated mixture at superatmospheric pressure is passed from theheater into a hydrogenation reactor which preferably is provided withmeans for maintaining the liquid contents thoroughly agitated and thesolid particles while suspended in the fluid. It is highly desirable tomaintain a completely liquid phase hydrogenation. Within thehydrogenation vessel under conditions of temperature and pressure givenabove, water readily reacts with metallic iron with the evolution ofhydrogen and the formation of iron oxide. The hydrogen reacts with thecoker distillate to be hydrogenated before molecular hydrogen(Z-hydrogen atoms per molecule) is formed. The freshly formed hydrogenis known as atomic or nascent hydrogen. By consuming the hydrogenimmediately and while it is in its atomic state, a highly efficientdegree of coker distillate hydrogenation is effected. It is alsopossible in the hydrogenation reactor under temperatures above 800 F. toeffect a destructive hydrogenation in which the boiling range of thehydrogenated product is lower than that of the coker distillate beinghydrogenated and the hydrocarbon produced from the reactor may bereadily vaporized.

A desulfurization reaction also occurs simultaneously with thehydrogenation whereby sulfur-containing hydrocarbon molecules aredecomposed and the fragments hydrogenated with the formation of hydrogensulfide and of hydrocarbons. At least a part of the hydrogen sulde thusformed reacts with the iron or the iron oxide to form iron sulfide whichis removed with the hydrogenated hydrocarbons from the reactor. Oxygenand nitrogen derivatives of hydrocarbons are also decomposed with theformation of water and ammonia, respectively. The water thus formed mayreact with additional quantities of iron to form hydrogen while theammonia dissolves in any excess water and may be recovered as an aqueousphase from the hydrogenated material.

The hydrogenated hydrocarbon stream passing from the hydrogenationreactor is suddenly depressured from the superatmospheric operatingpressure through one or a plurality of expansion valves to a pressure ator near atmospheric pressure such as from about l to l00 pounds persquare inch absolute. The material is subsequently passed through a coilin a heater and the combination of the expansion and the heating effectsa substantially complete vaporization of the hydrogenated effiuent. Thegaseous hydrocarbon stream thus produced carries with it suspendedparticles of iron which may be unreacted and with the iron oxide andiron sulfide. This vapor stream passes into a suitable separator whichmay comprise a cylindrical tower with a centrifugal separator disposedin the upper portion thereof. By means of the separator the suspended`solid matter is removed and passes over a series of baffles down throughthe tower countercurrent to a stripping gas such as steam which servesto rerixave remaining traces of liquids or gases from the so s.

The solids are removed from the lower part of the vessel, suspended in astream of air and conveyed as a suspension into the oxidizingregenerator referred to above in which the oxidation of iron sulfide iseffected in a fiuidized system. The combustion of iron sulfide to formiron oxide results in gases containing considerable quantities of sulfurdioxide. This gas may be chemically reduced by reaction with carbondioxide by combining oxidizing regenerator effluent with the properproportion of reducing regenerator effluent or producer gas so that thefollowing reaction occurs:

A substantial liberation of heat results which may be employed in awaste heater boiler to depleted high steam and simultaneously coolingthe sulfur-bearing gases to below about 250 F. to permit centrifugal orelectrical precipitation of the solid sulfur particles.

Returning now to the hydrogenated efiiuent separator, a vapor streamcomprising vapor phase hydrocarbon and water is removed from theseparator and introduced into the hydrogenator bubble tower whereby afractionation of the hydrogenated effluent is effected. Gases areproduced from the upper portion of the tower as well as a hydrogenatedand desulfurized gasoline gas oil and other hydrocarbon fractions ofdifferent boiling range. From one tray in the tower an aqueous phasecontaining ammonium hydroxide may be produced. The hydrogenatedhydrocarbon fractions thus produced comprise suitable raw materials forthe preparation of high grade internal combustion engine fuels, solids,lubricating oil and lubricating greases, etc. A small amount of residualmaterial remains in the system and may be produced as a bottoms productfrom the hydrogenator bubble tower and is returned and combined with thefeed stock to the system whereby it is recoked.

The fundamental advantage of this modification lies in the hydrogenationstep wherein a substantially complete separation of the unreacted ironif any and the solid iron compounds is effected by expanding thehydrogenator efuent from its superatmospheric pressure to substantiallycompletely vaporize the stream followed by a centrifugal separation ofthe solid products suspended in the gas. This modification of theoperation is readily carried out particularly when the lower boilingproducts are desirable such as the gasoliues and gas oils.

In the modifications of the process of this invention as glven above theoperating pressures in all cases except that of the hydrogenation are ator near atmospheric pressure. It is preferable to operate a uidizedsystem at pressures somewhat in excess of that of the atmosphere to aldin effecting proper control of the operation. Consequently the preferredpressure range for the operat1on of. the fiuidized coker, the reducingregenerator and the oxidized regenerator is from about zero pounds toabout pounds per square inch gauge, a pressure of about 30 pounds persquare inch gauge being well suited to this particular operation. Theoperation of the coker bubble tower and the hydrogenated effluent bubbletower 1n which hydrogenation distillations are effected are preferablyoperated at pressures in the same approximate pressure range.

As previously stated, the hydrogenation operation may be carried out atsuperatmospheric pressures as high as about i000 atmospheres or aboutl15,000 pounds per square mch. Operating pressures for the hydrogenationstep m the range of from about 3000 to 10,000 pounds per square inch arewell suited to effecting the desired results and operating pressures offrom about 4000 to about 7500 pounds per square inch have been foundsuitable.

In each modification, hydrogen generation arises from the reaction ofWater with a metal above hydrogen in the electromotive series, that iswith a metal capable of replacing hydrogen from water forming a metaloxide reducible by carbon. In the modifications described above iron hasbeen set forth as the metal. There are, however, other metals which arecapable of effecting this reaction to the desired extent. Among thesemetals are zinc, cobalt, nickel, manganese, and the like. This includesthe metals of atomic Nos. 25 through 30 of Il9 Mendeleefs'periodic'table of the' elements with thef exceptionof copper.-

In themoditication of thel process of this invention described above, asubstantially complete desulfuriz'ation of a hydrocarbon fractidriiiiay'beeffected by hydrogenation; This'i's ataomplished in thelziydrogenationy reactor under the temperature and pressure and otherconditions described' above. Another modification exists by means ofwhich desulfurizationnfi'ay be at least partially effected inthe colcingreactor' inwhich atl leastl aI part of the elemental iron produced' fromtheA reducing regenerator is combined'. with the hydrocarbon feedstreampassing into the' coker'. 'lhef presenceof.- elemental iron at cokingtemperatures sufficient to thermal-ly decompose sulfurcontaininghydrocarbon compounds permits the hydrogen sulfide thus liberated toreadily convert part of the iron to iron sulfide. The immediate effect;of incorporating elemental1 iron with the hydrocarbon stream tothe cokeris that ofreducii'ig thc'sultur content of the hydrocarbon fractionsproduced from the Coker bubble tower, and reducing the hydrogencontamination in' the hydrogenation step of the; combination process.

In the modificrationsv of the process of this invention described above,exclusive reference has' been made to the treating of heavy' gravitycrude petroleums by' means of which these hydrocarbons are coked in4 thepresence of iron oxide, the' coke-laden iron oxide is suitably treatedto reduce the iron oxide to iron; and the iron is reacted with Water inthe presence of at least' part' of the hydrocarbon' products obtainedduring the coking reaction to form hy'dr'ogenatedand desulfu'rizedliquid and hydrocarbon fractions. It should not be understood that theprocess of this invention is exclusively applicable to the treating ofpetroleum hydrocarbons since similar desirable results may be broughtabout in employing the heavy gravity oils 'and tars obtained from coaldistillation as feedstock. These tars and oils. are essentially aromaticin nature'co'n't'airi'ing high molecular weight condensed ringstructures and include such materials as benzene, toluene, xylene,naphthalene, anthracene, phenanthr'ene, lirysene, picene, and otherpolynucleur aromatic as lwell as heter'ocyelic compounds'. Variouscondensedl struc-'tures such as ind'eneV and tiuorene, as well as thehigher rnolecu'lar weight aromatic acids known as phenols andl thehigher molecular weight aromatic bases of the pyridine type'l alsooccur. By employing such cal tar frac-'tions as feed stock in theprocess` of this invention; desirabl'y lower boiling hydrocarbonfractions may beobtaii'ied which may contain a variable quantity ofresidual aromatic hydrocarbons and may also containpv-rfible quantitiesof cyclic saturated hydrocarbons of the riaphthene-typeas Well* asparafiinic hydrocarbons depending upon the severityr of the coking andof the-hydrogeiiatio step. Highly desirable hydrocarbon fractions rn'ybe readily obtained from this type of feedy stock.v

The process, according tothis invention may be further applied to thehydrogenation of normally solid carbonaceoiis materials of whichexamples are bituminous coal, lignite,- peat, brown coal, and the like.The process of this inventionis modified to the extent that thecarbonaceous material or coal' to be treated is finely pulverized in asuitable grinding mill' and mixed with a tar recycle to form a paste-oraliquid suspension of coal solids in the oil. This tar recycle 'may beone obtained from the coker wherein the paste is coked with theliberation of further quantities of aromatic type coal tars or it maybea residual oil froml the hydrogenation effluent bubble tower whichdesirabl'yl is reprocessed. During the operationV of this modificationof the process iron oxide produced from the oxidiiing regenerator iscombined with the paste and introduced into the coker or it may beintroduced into the Coker directly. The hydrocarbon oils liberated fromthe coal during coking are subsequently mixed with iron, for example,and water and hydrogenatedundr high pressure as previously described.Such materials as oil sand, tar sand, oilsoaked diatofnite may betreated in a manner similar to that described above for handlingcarbonaceous solids such as coal.

The process of the present invention described' in detail above permitsthe ready'c'tnivrsit'in` of' carbonaceous materials whether theyare-solids' or liquids to desirable hydrocarbon fractions substantiallyfree of' contaminating elements by a combined" operation of coking inthe presence ofa metal. oxide depositing' a carbonaceous solid on themetal oxide, andlhydrogenating the` thermal pyrolysis product obtainedduring the coking operation by reacting the metalf with water under highpressure and temperature to produceA hydrogen. The process eliminatesthe disadvantages inherent in previous hydrogenation processes, namely,the requirement' for expensive and sensitive hydrogenation catalysts',the requirement for extensive hydrogen compression facilities, andothers.

A particular embodiment of the present invention has been described inconsiderable detail by way of illustration. It should be understood thatvarious other modifications and adaptationsl thereof may be made bythose skilled in this particular art without departing from the spiritand scope of this invention as set forth' in the appended claims.

We claim:

l. An apparatus for the refining of hydrocarbons which comprises ahydrocarbon pyrolysis vessel, an inlet conduit for hydrocarbon openinginto the lower part thereof, an outlet conduit for pyrolysis productopening from the upper part thereof, a reducing vessel, a conduit forsolids communicating said pyrolysis vessel with said reducing vessel, aninlet conduit for gas opening into the lower part thereof, an outlet forgas opening from the upper part thereof, an outlet for solids openingfrom the bottom thereof, a heating means, an inlet conduit theretocommunicating with said outlet conduit for pyrolysis product openingfrom said pyrolysis vessel and with said outlet for solids opening fromsaid reducing vessel, an elongated reactor vessel, a movable agitatormeans extending longitudinally throughout the entire length thereof,motive means for actuating said agitator means, a conduit communicatingthe outlet of said heating means with an inlet at one end of saidreactor vessel, outlet means opening from the other end thereof, apumping means, a first recycle conduit directly communicating said otherend of lsaid reactor vessel through said pumping means with said heatingmeans, hydrocarbon separator means communicating with said outlet meansfrom said reactor vessel, an outlet for hydrocarbon product openingtherefrom, and a second recycle conduit for hydrocarbon and solidscommunicating said separator means ultimately with said pyrolysisvessel.

2. An apparatus for the refining of hydrocarbons which comprises incombination a hydrocarbon coking vessel, a reducing vessel and anelongated reactor vessel, a first heating means, an inlet conduit forhydrocarbon opening thereinto, a conduit opening from said first heatingmeans into the lower part of said coking vessel, an outlet conduit forcoker distillate opening from the upper part of said Coking vessel, aconduit for solids communieating the lower part of said coking vesselwith said reducing vessel, an inlet conduit for gas opening into thelower part thereof, an outlet conduit for gas from the upper partthereof, an outlet for solids opening from the bottom thereof, a secondheating means, an. inlet conduit thereto communicating with said outletconduit opening from the upper part of said coking vessel and with saido utlet for solids opening from the lower part of said reducing vessel,a conduit opening from the outlet of said second heating means and intothe lower end of said reactor vessel, a movable agitator meansextendinglongitudinally throughout thel entire length thereof motivemeans for actuating said agitator, a pumping means, a first recycleconduit communicating directly from said upper end of said reactorthrough said pumping means with the inlet conduit into said secondheating means, a hydrocarbon distillation column, a conduitcommunicating the upper end of said reactor vesselwith said distillationcolumn, means for removing hydrocarbon product therefrom, and a secondrecycle conduit communicating the lower end of said column with theinlet conduit to said first heating means.

3. apparatus f or the refining of hydrocarbons which comprises 1ncombination a coking vessel, a reducing vessel, an oxidizing vessel andan elongated reactor vessel, an inlct conduit for hydrocarbon openinginto the lower part of said coking vessel, anoutlet for cokedhydrocarbons opening from the upper part thereof, a conduit for solidsopening from the lower part of said coking vessel into said reducingvessel, an inlet conduit for gas opening into the lower part of` saidreducing vessel, an outlet for gas opening from the upper part thereof,a solids fractionation means, a conduit for solids opening from thelower part of said reducing vessel into sald fractionation means, a rstconduit for solids therefrom opening into the lower part of saidoxidizing vessel, means for introducing gas into the lower part thereof,an outlet conduit for gas from the upper part thereof, a conduit forsolids opening from the lower part of said oxidizlng vessel into saidreducing vessel, a second conduit for solids opening from said solidsfractionation means, a solids and liquid mixing means communicating wlthsaid second conduit for solids and with said outlet from the upper partof said coking vessel, an inlet condult for water into said mixingmeans, a heating means, a conduit opening therento from said mixingmeans, a conduit opening therefrom into the bottom of said elongatedreactor vessel, a movable agitator means extending longitudinallyentirely through-said reactor vessel, motive means for actuating saidagitator, a pumping means, a first recycle conduit communicatingdirectly from the top of said reactor vessel ythrough said pumping meansto the inlet to said heating means, a hydrocarbon fractionation meansconnected in hydrocarbonreceiving relation with the top of said reactorvessel, at least one outlet conduit from said fractionation means, and asecond recycle conduit communicating said fractionation means with saidcoking vessel.

4. An apparatus for the refining of hydrocarbons which comprises incombniation a coking vessel, a reducing vessel, an oxidizing vessel, avertical elongated reactor vessel, and a second reactor vessel, a lirstheating means, an inlet conduit thereto for hydrocarbon feed, an outletconduit therefrom opening into the lower part of said colting vessel, anoutlet for coked hydrocarbons opening from the upper part thereof, aconduit for solids opening from the lower part of said coking vesselinto said reducing vessel, an inlet conduit for gas opening into thelower part of said reducing vessel, an outlet for gas opening from theupper part thereof into said second reactor vessel, a solidsfractionation means, a conduit for soilds opening from the lower part ofsaid reducing vessel into said fractionation means, a first conduit forsolids opening from the lower part of said resad oxidizing vessel, meansfor introducing gas into the lower part thereof, an outlet conduit forgas from the upper part thereof opening into said second reactor vessel,a conduit for solids opening from the lower part of said oxidizingvessel into said reducing vessel, a cooling means, an outlet conduitfrom said second reactor vesse opening into said cooling means, aseparator, a conduit opening thereinto from said cooling means, anoutlet for gas from said separator, a second outlet for sulfurtherefrom, a second conduit for solids opening from said solidsfractionation means, a solids and liquid mixing means communicating withsaid second conduit for solids and with said outlet from the upper partof said coking vessel, an inlet conduit for water into said mixingmeans, a heating means, a conduit opening thereinto from said mixingmeans, a conduit opening therefrom into the bottom of said elongatedreactor vessel, a movable agitator means extending longitudinallyentirely through said reactor vessel, motive means for actuating saidagltator, a pumping means, a first recycle conduit communieatingdirectly from the top of said reactor vessel through said pumping meansto the inlet to said heating means, a hydrocarbon fractionation meansconnected in hydrocarbon-receiving relation with the top of said reactorvessel, at least one outlet conduit from said fractionation means, and asecond recycle conduit communicating said fractionation means with saidcoking vessel.

5. An apparatus according to claim 4 wherein said solids fractionationmeans comprises a continuous magnetic separator.

6. An apparatus according to claim 4 in combination with a solids-gascontacting means, an inlet conduit for solids opening into saidcontacting means at one end thereof from the lower portion of saidreducing vessel, an inlet conduit for gas opening into one end of saidcontacting means from the outlet of said second reactor vessel, anoutlet conduit for solids from the opposite end of said contacting meansfrom said inlet conduit for solids opening thereinto and whichcommunicates with the solids inlet to said oxidizing vessel, and anoutlet for gases at the opposite end of said contacting means from saidinlet conduit for gas opening thereinto.

7. An apparatus according to claim 4 wherein said hydrocarbonfractionation means comprises in combination a ash vaporizer means and avapor-solids separator and a conduit opening therebetween, an outletconduit for vapor from said separator, and an outlet conduit from thelower part thereof communicating with said second recycle conduit.

8. An apparatus according to claim 4 in combination with an auxiliarysolids-gas contacting vessel, an inlet conduit for gas opening into thelower part thereof from the upper part of said reducing vessel, an inletconduit for solids opening from the lower part of said yoxidizing vesselinto the upper portion of said auxiliary vessel, an outlet conduit forgas opening from the upper part thereof, and an outlet conduit forsolids opening from the lower part thereof and into said reducingvessel.

9. An apparatus according to claim 4 wherein said hydrocarbonfractionation means comprises a distillation column, at least one outletconduit therefrom for distillates, and an outlet conduit from the bottomthereof which communicates with said second recycle conduit.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,266,161 Campbell et al Dec. 16, 1941 2,311,978 Conn Feb. 23,1943 2,325,611 Keranen Aug. 3, 1943 2,379,027 Monro June 26, 19452,434,567 Jahnig et al. Jan. 13, 1948 2,483,512 Voorhies, Jr., et al.Oct. 4, 1949 2,540,706 Beck et al. Feb. 6, 1951

1. AN APPARATUS FOR THE REFINING OF HYDROCARBONS WHICH COMPRISES AHYDROCARBON PYROLYSIS VESSEL, AN INLET CONDUIT FOR HYDROCARBON OPENINGINTO THE LOWER PART THEREOF, AN OUTLET CONDUIT FOR PRYOLYSIS PRODUCTOPENING FROM THE UPPER PART THEREOF, A REDUCING VESSEL, A CONDUIT FORSOLIDS COMMUNICATING SAID PYROLYSIS VESSEL WITH SAID REDUCING VESSEL, ANINLET CONDUIT FOR GAS OPENING INTO THE LOWER PART THEREOF, AN OUTLET FORGAS OPENING FROM THE UPPER PART THEREOF, AN OUTLET FOR SOLIDS OPENINGFROM THE BOTTOM THEREOF, A HEATING MEANS, AN INLET CONDUIT THERETOCOMMUNICATING WITH SAIDOUTLET CONDUIT FOR PYROLYSIS PRODUCT OPENING FROMSAID PYROLYSIS VESSEL AND WITH SAID OUTLET FOR SOLIDS OPENING FROM SAIDREDUCING VESSEL, AN ELONGATED REACTOR VESSEL, A MOVABLE AGITATOR MEANSEXTENDING LONGITUDINALLY THROUGHOUT THE ENTIRE LENGTH THEREOF, MOTIVEMEANS FOR ACTUATING SAID AGITATOR MEANS, A CONDUIT COMMUNICATING THEOUTLET OF SAID HEATING MEANS WITH AN INLET AT ONE END OF SAID REACTORVESSEL, OUTLET MEANS OPENING FROM THE OTHER END THEREOF, A PUMPINGMEANS, A FIRST RECYCLE CONDUIT DIRECTLY COMMUNICATING SAID OTHER END OFSAID REACTOR VESSEL THROUGH SAID PUMPING MEANS WITH SAID HEATING MEANS,HYDROCARBON SEPARATOR MEANS COMMUNICATING WITH SAID OUTLET MEANS FROMSAID REACTOR VESSEL, AN OUTLET FOR HYDROCARBON PRODUCT OPENINGTHEREFROM, AND A SECOND RECYCLE CONDUIT FOR HYDROCARBON AND SOLIDSCOMMINICATING SAIS SEPARATOR MEANS ULTIMATELY WITH SAID PYROLYSIS VESSEL